package com.telerobot.fs.utils;
import java.io.ByteArrayOutputStream;
import java.io.IOException;

public class WaveHeader {
	public final char fileID[] = {'R', 'I', 'F', 'F'};
	   public int fileLength;
	   public char wavTag[] = {'W', 'A', 'V', 'E'};;
	   public char FmtHdrID[] = {'f', 'm', 't', ' '};
	   public int FmtHdrLeth;
	   public short FormatTag;
	   public short Channels;
	   public int SamplesPerSec;
	   public int AvgBytesPerSec;
	   public short BlockAlign;
	   public short BitsPerSample;
	   public char DataHdrID[] = {'d','a','t','a'};
	   public int DataHdrLeth;

	public byte[] getHeader() throws IOException {
	   ByteArrayOutputStream bos = new ByteArrayOutputStream();
	   WriteChar(bos, fileID);
	   WriteInt(bos, fileLength);
	   WriteChar(bos, wavTag);
	   WriteChar(bos, FmtHdrID);
	   WriteInt(bos,FmtHdrLeth);
	   WriteShort(bos,FormatTag);
	   WriteShort(bos,Channels);
	   WriteInt(bos,SamplesPerSec);
	   WriteInt(bos,AvgBytesPerSec);
	   WriteShort(bos,BlockAlign);
	   WriteShort(bos,BitsPerSample);
	   WriteChar(bos,DataHdrID);
	   WriteInt(bos,DataHdrLeth);
	   bos.flush();
	   byte[] r = bos.toByteArray();
	   bos.close();
	   return r;
	}

	private void WriteShort(ByteArrayOutputStream bos, int s) throws IOException {
	   byte[] mybyte = new byte[2];
	   mybyte[1] =(byte)( (s << 16) >> 24 );
	   mybyte[0] =(byte)( (s << 24) >> 24 );
	   bos.write(mybyte);
	}


	private void WriteInt(ByteArrayOutputStream bos, int n) throws IOException {
	   byte[] buf = new byte[4];
	   buf[3] =(byte)( n >> 24 );
	   buf[2] =(byte)( (n << 8) >> 24 );
	   buf[1] =(byte)( (n << 16) >> 24 );
	   buf[0] =(byte)( (n << 24) >> 24 );
	   bos.write(buf);
	}

	private void WriteChar(ByteArrayOutputStream bos, char[] id) {
	   for (int i=0; i<id.length; i++) {
	      char c = id[i];
	      bos.write(c);
	   }
	}
	}

